The broad aim of this proposal is to develop an evolutionary demography of lifespan in the wild. The proposed program will consist of the following six projects: Project 1 titled Caste demography and aging in honey bees and directed by Robert Page (Arizona) will address questions concerned with how the honeybee ovary is involved in post emergence development, life history development, reproduction, and life span. Project 2 titled Ecology of lifespan and directed by James Carey (UC Davis) will involve field studies on the medfly in Greece and butterflies in Uganda to ask questions about aging, lifespan, and impairment of insects in the wild. New statistical models for estimation of survival and age structure in the wild will also be developed on this project. Project 3 titled The mathematical demography of biodemography and directed by Kenneth Wachter (UC Berkeley). The project will combine models for mutational load with the other two main strands of evolutionary life-course modeling including Markov processes and optimal life history models. Project 4 titled Natural ecology of stress and aging in C. elegans and directed by Thomas Johnson (Colorado) and Patrick Phillips (Oregon) will be investigating the role that variable environmental inputs play in modulating the demography of C. elegans in a strain-specific way. Project 5 titled Evolutionary dynamics of life span and directed by Shripad Tuljapurkar aims to describe variation in life history phenotypes that significantly affect fitness, and to analyze empirically and theoretically the forces that maintain variation and shape life histories and lifespan. Project 6 titled Ecology of the lifespan in subsistence peoples and directed by Hillard Kaplan (New Mexico) and Michael Gurven (UC Santa Barbara) will involve studies on the Tsimane of Bolivia that are concerned with age-specific contributions to fitness among older individuals in traditional societies. The program will involve major synergistic components including biannual meetings, interactions of three focus groups involving researchers from multiple projects, and a series of seven different mini- workshops designed to foster greater communication between members from different projects and to provide a mechanism for engaging researchers from outside the program. Three of these workshops will be held at research field sites including Kibale National Park, Uganda (Project 2), Rum Island, Scotland (Project 5), and Bolivia (Project 6).